The thyroid and parathyroid glands

The thyroid is an endocrine gland. This means that the thyroid makes and releases hormones. The hormones released by the thyroid are triiodothyronine (T3), Thyroxine (T4) and calcitonin. In combination, these hormones  control  the mineral  content  of the  blood and the body’s metabolic rate which in turn controls the body temperature and body fat.

In order to make the T3 and T4 hormones, the thyroid requires iodine, a chemical element found naturally in many foods. The thyroid absorbs the iodine and through several chemical reactions, produces the T3 and T4 hormones.

Adjoined to the thyroid gland are the parathyroid glands, also a type of endocrine gland. There are four parathyroid glands and these glands produce a hormone called the parathyroid hormone. This hormone controls the levels of three minerals in the bloodstream; calcium, phosphorous and magnesium. These minerals are essential ingredients in maintaining bone health.

There are two benign thyroid diseases:

1. Hyperthyroidism (overactive thyroid)

In hyperthyroidism (also known as thyrotoxicosis), the thyroid produces too much thyroxine (T4). The imbalance in thyroxine causes an unwanted change in the body’s metabolic rate, causing symptoms including an increase in unexplained weight loss, restlessness, anxiety, and sweating. Without treatment it can lead to osteoporosis (bone fragility) or cardiomyopathy and other heart issues. Hyperthyroidism is mainly caused by Graves’ disease, an autoimmune disease where the immune system produces antibodies that stimulate the thyroid resulting in increased thyroxine levels.

2. Hypothyroidism (underactive thyroid)

In hypothyroidism, the thyroid produces too little thyroxine. This slows down the body’s metabolic rate, leading to feelings of tiredness or unexplained weight-gain. While it may occur through an autoimmune disease, hypothyroidism, while un-common, may also be a by- product  of  the  treatment  of  hyperthyroidism  where  too  much  of  the  thyroid  has  been surgically removed or ablated. Hypothyroidism is easily controlled through thyroxine (taken daily).